Motor vehicle dryer

ABSTRACT

The dryer for a motor vehicle washing and drying system includes three downwardly-facing nozzles. The nozzles oscillate in a synchronized manner, with two side nozzles oscillating over a limited range only. A center nozzle, disposed between the two side nozzles, oscillates over a wider range to drive water on the upper surface of the vehicle towards the side nozzles. The side nozzles then drive the water along the contours of the vehicle surface down the sides of the vehicle using the Coanda effect. One of the side nozzles as well as the center nozzle is moved in an inward or outward direction depending upon the sensed width of the vehicle. The center nozzle is rotated in a forward or rearward direction as the vehicle moves underneath the dryer. Each nozzle contains a unique ovoid-shaped member disposed in the nozzle to accelerate and concentrate the output of the nozzles. The distance between the vehicle and the center nozzle is sensed by a triangulation sensor so that the output of the center nozzle may be adjusted as the height of the vehicle varies, and so that the center nozzle may be rotated in the forward or rearward direction.

This application is a divisional of application Ser. No. 08/324,351filed Oct. 17, 1994 U.S. Pat. No. 5,596,818.

BACKGROUND OF THE INVENTION

This invention relates to commercial systems for washing and dryingmotor vehicles, such as those used in automatic car washes. Moreparticularly, this invention relates to dryers used in motor vehiclewashing and drying systems.

Several systems are known for automatically washing and drying motorvehicles. In a typical prior art system, a motor vehicle is driven ontoa track which is used to mark or register one side of the vehicle. Thevehicle then either remains stationary, or is moved as the washing anddrying operations are performed. The location of the opposite, passengerside of the vehicle is typically determined by the washer using acontact sensor that engages the passenger side of the vehicle. Thecontact sensor outputs a signal indicative of the width of the vehicle,so that the washing system may adjust the proximity and/or movement ofthe washing brushes accordingly.

After the motor vehicle has been washed, it is typically dried by adryer that includes one or more nozzles. The nozzles may oscillate orthey may be stationary. In a typical prior art system, described inReissue Pat. No. 33,334 issued Sep. 18, 1990, two oscillating nozzlesare used to output high velocity air onto the motor vehicle. The nozzlesoscillate over a wide angular range in an attempt to push the watertoward the center of the vehicle and then down the front and down therear of the vehicle. One of the nozzles is directed slightly toward thefront of the vehicle, and the other nozzle is directed slightly towardthe rear of the vehicle.

The vehicle dryer described in Reissue Pat. No. 33,334, as describedabove, has several disadvantages. First, the distance between the twoopposed nozzles is not adjustable to accommodate vehicles of differentsizes. Thus, the distance between the nozzles and the motor vehiclevaries significantly depending upon whether a minivan, for example, isbeing dried or whether a small commuter-type automobile is being dried.

Another disadvantage of such prior art systems is that a significantamount of water remains on the motor vehicle after the drying cycle hasfinished. In such prior art systems having two nozzles, the oscillatingnozzle tends to direct the water towards the central and furthermost topsurfaces of the motor vehicle being dried. Since the movement of thewater off the vehicle's surface is determined by the duration andmomentum of the air from the nozzle, the surface areas furthest from thenozzle are not adequately dried, in part, because the air loses momentumbefore the air reaches the most distant surface areas.

Another reason that such prior art systems achieve incomplete drying isdue to the nature of the oscillation cycles of their oscillatingnozzles. In a typical prior art system, the nozzles are oscillated byair cylinders. The use of air cylinders results in oscillation cycleshaving a velocity profile over time that resembles a rectangularwaveform. When two opposed oscillating nozzles are positioned as inReissue Pat. No. 33,334, this velocity profile of a first nozzle causessome water to be moved to the central portion of the top vehiclesurface, where the water remains until the second nozzle then pushesthis water back to the place where it previously had been located, nearthe first nozzle. Thus, some of the water simply moves back and forthinstead of being removed from the vehicle surface.

This back and forth movement of the water may be lessened to a certaindegree by moving the dryer apparatus over the vehicle twice at a veryslow speed, thereby substantially increasing the air's contact time withthe vehicle. A substantial portion of the water will then be driven offthe vehicle. However, this solution is unsatisfactory because theduration of the drying cycle is substantially increased to two or moreminutes, thereby reducing the number of vehicles that can be dried in agiven time period.

There are other drawbacks to prior art drying systems. For example, thetypical prior art system has oscillating nozzles that oscillate at highcycle rates over wide angles of oscillation, on the theory that it isbest to cover as much surface area as possible. In fact, however, thehigh cycle rates and wide angles of oscillation still result insignificant amounts of water being left on the vehicle.

Another problem with typical prior art dryers is that the high velocityair output by the nozzles tends to lose much of its velocity anddirection before the air has a chance to impinge on the more distantportions of the vehicle, such as the lower, side door panels and thecentral front and rear portions of the vehicle. One of the causes ofthis problem is that turbulent, ambient air in the dryer environmenttends to diffuse the nozzle output air as the output air travels moredistance from the nozzle.

SUMMARY OF THE INVENTION

An improved compact dryer system is provided for automatically dryingmotor vehicles, in which a higher proportion of the water is removedfrom the vehicle when compared to prior art dryers.

In a preferred embodiment, the dryer according to the present inventionincludes three spaced nozzles supported overhead by a support means. Afirst nozzle is directed toward the passenger portion of the vehicle, asecond nozzle is directed towards the driver's side of the vehicle, anda center nozzle, disposed between the first and second nozzles, isdirected towards a central portion of the vehicle. The dryer includes ablower means for providing a high velocity gas such as air to all of thenozzles. The nozzles are oscillated in a synchronized manner by anoscillating means. The positions of the nozzles on the support means andthe velocity profile of oscillation by the oscillation means areselected such that the high velocity gas output by the nozzles tends tofollow the vehicle surface to drive the water droplets off the vehicle.

The preferred embodiment also includes a means for changing the distancebetween the nozzles to accommodate vehicles of varying sizes. Aphotoelectric sensor supported by the support means outputs a light beamwhile the distance between the nozzles is being changed. The presence ofthe vehicle prevents the reflection of the light beam. When the lightbeam is reflected by a floor reflector and received by the photoelectricsensor, the sensor outputs a signal indicative of the width of thevehicle. The distance between the nozzles is then changed so that thecenter nozzle is centered across the width of the vehicle, and the firstnozzle is disposed generally above the passenger side of the vehicle.

The invention also includes a means for sensing the distance between thecenter nozzle and the upper surface of the motor vehicle, and forchanging the output of the center nozzle as a function of that distance.This feature enables the output of the center nozzle to be decreasedwhen the roof of the vehicle is passing underneath the center nozzle,and to be increased when either the front or the rear of the vehicle isbeneath the center nozzle. This feature also permits the output of thecenter nozzle to be decreased when a high vehicle--such as a minivan--isbeing dried to prevent denting of the vehicle's roof by the highvelocity air. When the output of the center nozzle is decreased, theoutputs of the two side nozzles are correspondingly increased.

Another key feature of the present invention is that the center nozzlemay be rotated from a first position at which it is directed towards thefront of the vehicle, to a second position at which it is directedtowards the rear of the vehicle. This feature improves the drying of thevehicle since the output of the center nozzle is always leading theoutputs of the two side nozzles, thereby tending to force the watertoward the sides of the vehicles, whereupon the water is forced down thesides and off the vehicle by the side nozzles using the Coanda effect.The angular displacement of the nozzles during oscillation as well asthe rate of oscillation are also limited to improve vehicular drying.

It is a feature and advantage of the present invention to provide amotor vehicle dryer which more effectively removes water from thevehicle.

It is another feature and advantage of the present invention to providea vehicle dryer in which the air output by the nozzles has a highvelocity while using smaller blower components.

It is yet another feature and advantage of the present invention to usethe Coanda effect to drive water down the side contoured surfaces of thevehicle and off the bottom of the vehicle.

These and other features of the present invention will be apparent tothose skilled in the art from the following detailed description of thepreferred embodiments, and the drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic front view of the dryer system according to thepresent invention depicting the means for changing the distance betweenthe nozzles.

FIG. 2 is a diagrammatic view of the nozzles and the means foroscillating the nozzles, depicted from the front of the dryer.

FIG. 3 is a perspective diagrammatic view of the means for oscillatingthe nozzles.

FIG. 4 is a side diagrammatic view depicting the means for moving thecenter nozzle between a first rearward-directed position and a secondforward-directed position.

FIG. 5 is a front view of the dryer system with the front housing coverremoved, and with the passenger side nozzle in an outward position toaccommodate a wide vehicle.

FIG. 6 is a front view of the dryer system with the front housing coverremoved, and with the passenger side nozzle in an inward position toaccommodate a narrow vehicle.

FIG. 7 is a front view of the center nozzle assembly.

FIG. 8 is a side view of the center nozzle and the means for changingthe output of the center nozzle, taken along line 8--8 of FIG. 5.

FIG. 9 is a cross-sectional view of a nozzle blower, taken along line9--9 of FIG. 5.

FIG. 10 is a front view of the center nozzle assembly, shown in both thefirst and in the second position.

FIG. 11 is a side view of the center nozzle assembly.

FIG. 12 is a front view of the passenger's side nozzle assembly.

FIG. 13 is a diagrammatic view of a nozzle, depicting the airflow aroundthe ovoid-shaped member and out the discharge opening of the nozzle.

FIG. 14 is a cross-sectional view of a nozzle, taken along line 14--14of FIG. 13.

FIG. 15 is a cross-sectional view of a nozzle, taken along line 15--15of FIG. 13.

FIG. 16 is an end view of the nozzle discharge opening, taken along line16--16 of FIG. 13.

FIG. 17 depicts water droplets clinging to a side surface of a vehicle.

FIG. 18 depicts water droplets being driven off a bottom vehicularsurface using the Coanda effect according to the present invention.

FIG. 19 is a schematic diagram of the dryer control circuitry used inthe present invention.

FIG. 20 is a schematic diagram of the high voltage circuitry used topower the motors in the present invention.

FIG. 21 is a perspective view of a free standing dryer according to thepresent invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The dryer according to the present invention may be used as astand-alone unit, may be self-powered, or the dryer may be towed by awashing apparatus used to automatically wash motor vehicles. The dryerdepicted and described herein is assumed to be a stand-alone unit.However, the preferred embodiment is readily adapted to being towed orself-powered, and is provided with rollers on opposite ends to permitthe dryer to be towed along a track, as is well known in the art. FIGS.1, 2, 6 and 7 depict rollers 10 and 12 which roll along respectivetracks 14 and 16 when the dryer is being towed.

FIG. 21 is a perspective view of a stand-alone dryer according to thepresent invention. In FIG. 21, dryer 18 is supported by two opposed legs20 and 22. Legs 20 and 22 are secured to a concrete floor 24. Dryer 18is a very compact unit, having a length from the front to the rear ofthe dryer of about 38 inches. A countdown display counter 26 is attachedto a wall 28 of the car wash building.

Display counter 26 is desirable when stand-alone dryers are used becausein such cases, the operator of the vehicle is typically inside thevehicle during the washing and drying processes. The operator must keepthe vehicle under the stand-alone dryer unit for a specific amount oftime--on the order of one minute--for proper drying to occur. Displaycounter 26 displays the number of seconds remaining on the drying cycleand may also indicate to the vehicle operator when he should stop hisvehicle under the dryer and when he should proceed forward after thedrying cycle has been completed.

Referring again to FIG. 21, dryer 18 includes a first nozzle 30 disposedgenerally above the passenger portion of vehicle 32, a second nozzle 34generally disposed above the driver's side portion of vehicle 32, and acenter nozzle 36 that is disposed between first nozzle 30 and secondnozzle 34. Each of nozzles 30, 34 and 36 directs a high velocity gas,typically air, in a generally downward direction toward motor vehicle32. Nozzles 30 and 34 are angled rearward approximately 10° to 15° fromvertical toward the front of oncoming vehicle 32, with 15° being thepreferred angle. Nozzles 30 and 34 are fixed at this angle to improvewater removal from the vehicle. In the alternative, nozzles 30 and 34could be rotated to face rearward and thereafter rotated to faceforward, as is the case with center nozzle 36.

Center nozzle 36 preferably has a discharge opening that is greater inarea than the discharge opening areas of nozzles 30 and 34. Vehicle 32is positioned underneath dryer 18, between legs 20 and 22, and generallyunderneath nozzles 30, 34 and 36.

To reduce noise, nozzles 30, 34 and 36 and preferably made from an opencell polyurethane foam. This foam is covered by a skin of a latex orsimilar elastomeric material to protect the nozzles from moisture.

Also attached to floor 24 is a reflector 38, whose purpose will now bediscussed in connection with FIG. 1.

FIG. 1 is a front, diagrammatic view of dryer 18 of FIG. 21. FIG. 1depicts the manner in which the distance between nozzles 30 and 36 ischanged, as well as the manner in which the distance between nozzles 36and 34 is changed. The purpose of this distance changing means is toaccommodate motor vehicles of different sizes so that optimal drying ofthe vehicle is achieved. For example, if the motor vehicle is a smallautomobile such as vehicle 39, the distances between nozzles 30 and 36on one hand and nozzle 34 on the other hand will be decreased so thatnozzle 30 is directed generally over the passenger portion of thevehicle and nozzle 36 is centered over the center portion of thevehicle. If the vehicle is a pick-up truck or van such as vehicle 40(depicted in phantom), nozzles 30 and 36 will move to their respectiveoutermost positions (depicted in phantom) so that nozzle 30 is directedgenerally over the passenger side of the vehicle, and nozzle 36 is stillcentered over the roof of vehicle 40. Thus, the distances betweennozzles 30 and 36 and nozzles 36 and 40 are increased when a largervehicle is being dried.

If the vehicle is of an intermediate size such as vehicle 42 (depictedin phantom), nozzles 30 and 36 are moved to intermediate positions, alsoshown in phantom.

The mechanism for changing the distances between the nozzles operates inthe following manner. Referring to FIGS. 1, 5, 6 and 9, nozzle 30 startsat its innermost position (FIG. 1), which is the default position, whenno vehicle is being dried. Nozzle 30 is moved to the default positionafter a vehicle has been dried. Thereafter, nozzle 30 begins to move inan outward direction while a photoelectric sensor 44 outputs a lightbeam 44a that is reflected by reflector 38 when the motor vehicle is notpositioned in the way of the light beam. The movement of nozzle 30 isaccomplished by a reversible motor 46 whose output shaft is connectedvia a belt and pulley system 48 (FIG. 9) to a screw-threaded drive 50.Screw drive 50 is received in a receptacle assembly 52, which in turn isconnected to nozzle 30 via arms 54 and 56. When reversible motor 46turns in a first direction, belt 48 and screw drive 50 rotate to movenozzle 30 in a generally outward direction away from nozzle 34.

Receptacle assembly 52 is attached via a cable 58 and a pulley 60 to atrolley 62 that is interconnected with center nozzle 36. Cable 58 hasturnbuckles 59 (FIGS. 5 and 6) to allow the length of the cable to bechanged. The movement of trolley 62 is opposed by a return spring 64,which also pulls trolley 62 to the default position. Trolley 62 has fourrollers 66 which roll along a rail 68. One end 58a of cable 58 isattached to receptacle assembly 52, and the opposite end 58b of cable 58is attached to rail 68.

As receptacle assembly 52 moves in the generally outward direction, itpulls cable 58, thereby moving trolley 62 and center nozzle 36. However,the pulley system that connects trolley 62 to nozzle 30 is designed tocreate a 2:1 ratio, so that trolley 62 moves exactly one-half thedistance of nozzle 30. This arrangement insures that center nozzle 36 isalways centered over the vehicle.

Sensor 44 is interconnected with motor 46 via a wire 70 (FIG. 1). Sensor44 does not receive any significant amount of reflected light as long asthe motor vehicle is positioned below the light beam. As nozzle 30 andsensor 44 continue to move in a generally outward direction, light beam44a, emanating from sensor 44, will eventually not be broken by themotor vehicle, and will be reflected by reflector 38. At that point, thedistance changing mechanism knows that the width of the vehicle has beendetermined, and an output signal from sensor 44 is output on wire 70 tothe control circuitry (FIG. 19), which in turn informs motor 46 to stopoperation. When motor 46 stops, the positions of nozzles 30 and 36remain fixed, with nozzle 30 being generally located over the passengerportion of the vehicle, and nozzle 36 being disposed over the centerportion of the vehicle. When the drying operation has finished, nozzles30 and 36 move in a direction toward nozzle 34 to the default position,to await the approach of the next vehicle.

FIGS. 2 and 3 are diagrammatic views which depict the means foroscillating nozzles 30, 34 and 36. The nozzles are oscillated in asynchronized manner, with center nozzle 30 oscillating in a much greaterarc than side nozzles 30 and 34. Nozzle 36 preferably oscillates between30° to 40°, with 36° being preferred. That is, nozzle 36 will oscillatein a symmetrical manner from the vertical axis, so that nozzle 36oscillates a positive 18° in one direction from the vertical axis towardthe driver's side of the vehicle, and 18° in the opposite direction fromthe vertical axis toward the passenger's side of the vehicle. Thepurpose of the oscillation of nozzle 36 is to drive the water towardsthe sides of the vehicle, so that the water may be driven down the sidesof the vehicle by nozzles 30 and 34 using the Coanda effect.

As used herein, the term "Coanda effect" refers to the tendency offluids to cling to curved surfaces while passing over the surfaces. Inthe present invention, the air from the nozzles is directed such thatthe air flow tends to cling to the surface of the vehicle all the waydown the sides of the vehicle, thereby driving water droplets off thelower portions of the vehicle body.

The purpose of the oscillation of side nozzles 30 and 34 is primarily tocause the water to be driven along the contours of the sides of thevehicle, down the sides of the vehicle, and off the vehicle using theCoanda effect. In prior art dryer systems, the side nozzles wereoscillated over a very wide arcuate range, so that the largest possiblesurface area would be covered. However, the inventors herein havediscovered that the oscillation of the side nozzles should be limited toa much narrower arcuate range when compared to prior art devices, toprevent the side nozzles from driving water which is on top of thevehicle toward the center of the vehicle, as in prior art dryer systems.The inventors have discovered that superior drying is achieved when anoscillating center nozzle forces the water towards the sides of thevehicle, and the side nozzles oscillate only enough to allow the waterto follow the contours of the sides of the vehicle and down the vehiclesides.

The inventors herein have also discovered that superior drying isachieved when center nozzle 36 is rotated from a rearward-facingdirection, to a forward-facing direction, as depicted and described inconnection with FIG. 4 below. When center nozzle 36 is rotated in such amanner, while all of the nozzles are oscillating in synchronization, thewater is driven either forward or rearward on the vehicle by the centernozzle, as well as off the top of the vehicle by the center nozzle.Thereafter, the oscillating side nozzles, whose output air actually lagsthe output air of the center nozzle due to the center nozzle's rotation,drive the water down the sides of the vehicle and off the vehicle.

Referring to the preferred embodiment depicted in FIG. 2, it ispreferred that side nozzles 30 and 34 each oscillate about 2° to 6° fromthe vertical in their respective outward directions, with 4° beingoptimal. Nozzles 30 and 34 also preferably oscillate about 4° to 8° intheir respective inward directions toward the center of the vehicle,with 6° being optimal.

The rate of oscillation is also limited to optimize water removal. Priorart dryer nozzles typically oscillate at 30 or more cycles per minute.In the present invention, the rate of oscillation is preferably betweenabout 12 to 15 cycles per minute, to give the water time to be forcedoff the vehicle surfaces. Fifteen cycles per minute is preferred.

The actual means for achieving the oscillation is depicted in FIGS. 2and 3, as well as in FIGS. 5, 6, and 12. Referring to these figures, anoscillation motor 72 turns a rectangular or square shaft 74, which isconnected to rotate with the output shaft of motor 72. Spaced alongshaft 74 are a plurality of eccentric cams 76, 78 and 80. A first end82a of connecting rod 82 is connected to eccentric 76, with its oppositeend 82b being connected to an arm 84 that is attached to nozzle 30.Similarly, a connecting rod 86 has its first end 86a connected toeccentric 78 and its opposite end 86b connected to arm 88, arm 88 beingconnected to nozzle 36. Also, connecting rod 90 has a first end 90aconnected to eccentric cam 80, and its opposite end 90b connected to anarm 92. Arm 92 is connected to nozzle 34.

The use of a crank mechanism to oscillate the nozzles in the presentinvention yields an oscillation cycle for each nozzle having asinusoidal velocity profile over time. As an oscillating nozzle in thepresent invention swings to direct air toward the most distant portionof the vehicle surface, the velocity of the nozzle begins to decrease.This reduced velocity near the ends of the nozzle's travel increases theamount of air that contacts the water on the vehicle surface whencompared to prior art oscillating nozzles that have rectangularly-shapedvelocity profiles. This reduction in the nozzle velocity near the endsof nozzle travel compensates for the increased surface area that must becovered near the ends of nozzle travel, and for the drop in air momentumthat results from the increased distance between the nozzle and thevehicle surface area. Prior art oscillation systems using air cylindersdo not achieve nozzle oscillation velocity profiles in which nozzlevelocities are reduced near the ends of nozzle travel.

A major advantage of the oscillation mechanism according to the presentinvention is that the vehicle drying time is reduced to less than oneminute while achieving superior drying. Prior art dryer systems wouldrequire two minutes or longer to achieve very good results.

The oscillation system operates in the following manner. In response toa control signal, motor 72 rotates shaft 74. The rotation of shaft 74causes spaced eccentric cams 76, 78 and 80 to rotate with shaft 74. Therotation of cams 76, 78 and 80 causes their respective connecting arms82, 86 and 90 to reciprocate, as depicted by the arrows in FIGS. 2 and3. The reciprocation of connecting arms 82, 86 and 90 causes respectivearms 84, 88 and 92 to move through respective arcs 94, 96 and 98,thereby oscillating their respective nozzles 30, 36 and 34. Arcs 94 and98 are preferably 6°, with a range of 4° to 8° being acceptable. Arc 96is preferably 36°, with a range of 30° to 40° being acceptable.

FIG. 10 is a front view of center nozzle 36, depicting the position ofthe nozzle at both extremes of its oscillation travel. FIG. 11 is a sideview of nozzle 36. FIG. 12 is a front view of nozzle 30, depicting themovement of nozzle 30 in response to the rotation of shaft 74 and to thereciprocation of connecting rod 82 and arm 84.

As mentioned above, another feature of the present invention is thatcenter nozzle 36 may be rotated or moved from a first position at whichit is directed towards the front of the vehicle (rearward-facing), andthen to a second position at which it is directed toward the rear of thevehicle (forward-facing). As the vehicle passes underneath the centernozzle, or as the center nozzle is towed with the dryer above thevehicle, the center nozzle rotates in response to the change of thedistance between the upper surface of the vehicle and the center nozzle.This change in the distance is detected by a sensor 104 (FIG. 4); thechange in this distance corresponds to the transitions from the front tothe rear of the vehicle.

This rotation of the center nozzle is best shown in the diagrammaticview of FIG. 4. In FIG. 4, nozzle 36 is interconnected with an aircylinder 100 which rotates nozzle 36 about a pivot 102. Air cylinder 100is operated in response to a control signal from the control circuitry(FIG. 19).

In FIG. 4, the position of nozzle 36 and the operation of cylinder 100are determined by the distance between a proximity sensor 104 disposednext to nozzle 36 and an upper surface 106 of motor vehicle 108. Sensor104 is preferably a through beam type sensor.

In FIG. 4, sensor 104 outputs a light signal 110 that is reflected backto sensor 104 when upper surface 106 of vehicle 108 is detected. Nozzle36 is initially directed towards the front of the vehicle since thefront of the vehicle is always the first to pass underneath nozzle 36.This position of nozzle 36 is depicted as position 112 of FIG. 4.Position 112 is about 10° to 20° from vertical, with 15° to 18° beingthe preferred range.

Thereafter, nozzle 36 maintains position 112 as long as sensor 104produces an output signal. The output signal of sensor 104 ceases whenthe roof of the vehicle passes under sensor 104, since at that time thedistance between sensor 104 and vehicle surface 106 is less than apredetermined minimum distance. The sensor output signal is thereaftergenerated when the trunk of the vehicle--or the rear of the vehicle, incase of a van--is encountered. At that time, nozzle 36 rotates betweenabout 13° to 30° until it is repositioned to a forward-facing position,depicted as position 120 in FIG. 4. Position 120 is about 3° to 10° fromvertical, with 5° being the preferred angle. Nozzle 36 remains inposition 120 until the drying cycle is completed.

In summary, nozzle 36 is rotated, as depicted in FIG. 4, to thatposition which optimally drives the water disposed on upper surface 106down one of the side surfaces of the vehicle, so that nozzles 30 and 34(FIG. 2) may then drive the water down the sides and toward the rear ofthe vehicle.

FIGS. 7 and 11 both depict air cylinder 100, which is used to rotatecenter nozzle 36, as discussed above in connection with FIG. 4. FIG. 11more particularly depicts the operation of air cylinder 100.

As best shown in FIGS. 5 and 6, each of nozzles 30 and 34 is suppliedwith a high velocity gas, such as air, from their respective blowers 126and 128. Blower 126 is operated by a blower motor 130, which has apulley 132 attached to its drive shaft. A belt 134 engages pulley 132and a corresponding pulley 136 on fan 126. Similarly, blower 128 ispowered by a blower motor 138 which has a pulley 140 attached to itsdrive shaft. Pulley 140 engages a belt 142, the latter engaging a pulley144 on fan 128.

Fans 126 and 128 are commonly-available 15 hp fans, except that theirsidewalls or scrolls have been modified to increase the volume output ofthe fans. In FIG. 5, scroll 126a of fan 126 has been moved radiallyoutward from the center of blower 126, when compared to thecommercially-available scroll, whose position would be at position 126b.Likewise, scroll 128a of fan 128 has been moved radially outward, whencompared to position 128b of the scroll that is commercially-available.

To further increase the volume output of blowers 126 and 128, cutbackplates 146 and 148 have been added to their respective nozzle assemblies30 and 34. Cutback plates 146 and 148 direct more of the air output fromblowers 126 and 128 respectively into their respective nozzles 30 and34, to also increase the output of the nozzles.

Air is provided to nozzle 36 from both blowers 126 and 128. This isaccomplished by having an air conduit 150 connected between fan 126 andnozzle 36, and a similar conduit 152 connected between fan 128 andnozzle 36. Thus, each of blowers 126 and 128 supplies high velocity airto two nozzles. Blower 126 supplies air to nozzles 30 and 36, and blower128 supplies air to both nozzles 34 and 36.

The flow of air to nozzle 36 is controlled by an air reducing ordampening means which changes the output of the center nozzle as afunction of the distance between the center nozzle and the upper surfaceof the motor vehicle. The output of the center nozzle is reduced toprevent damage to the roof of the vehicle when the high velocity aircomes in contact with the vehicle roof.

The means by which the air supplied to center nozzle 36 is reduced isbest shown in FIGS. 7 and 8. The dampening means in FIGS. 7 and 8 isresponsive to the output of sensor 104 (FIG. 4), which sensor and itsassociated control circuitry (FIG. 19) compute the distance betweenupper surface 106 (FIG. 4) of vehicle 108 and center nozzle 36. Inresponse to this distance computation, the control circuitry (FIG. 19)outputs a control signal to relay 154. In response to the controlsignal, relay 154 rotates a butterfly valve plate 156 via crank arm 158.The flow of air through conduit 160 is reduced as valve plate 156 isrotated from the vertical position depicted in FIGS. 7 and 8 to anon-vertical position. As the airflow through conduit 160 is reduced,the airflows to nozzles 30 and 34 (FIG. 5) are correspondinglyincreased. In other words, when a lower volume of air is required topush the water off of a relatively high vehicle roof, additional airflowis provided to the side nozzles since the side surfaces of the vehiclewill tend to be larger, in that the distance between center nozzle 36and the roof of the vehicle tends to be inversely proportional to thesurface areas of the sides of the vehicle.

FIGS. 13 through 16 all relate to another feature of the presentinvention, namely that air output from a nozzle has both its velocitycomponent and its direction component in the desired direction of travelincreased as a result of the placement of an ovoid-shaped member of thecentral portion of the nozzle. As used herein, the term "ovoid-shaped"refers to a three dimensional shape which is substantially the shape ofa football, and is sometimes referred to as "egg-shaped", or an inflatedthree-dimensional oval shape. In FIG. 13, ovoid-shaped element 162 isdisposed within each of the nozzles 30, 34 and 36 such that element 162is centered within the nozzle near discharge end 164 of the nozzle. Theshape of element 162 causes the airflow, indicated by arrows 166, tofollow outer surface 162a of element 162 due to the Coanda effect. Atthe same time, those portions of the airflow closest to curved wall 168of the nozzle, indicated by arrows 170, are also accelerated andchanneled in a proper direction due to the constriction resulting fromthe placement of element 162 within the nozzle. This constriction isbest shown in FIG. 15.

To reduce noise, ovoid-shaped member 162 is made from an open cellpolyurethane foam. The foam is protected from moisture by coveringmember 162 with a skin made from latex or a similar elastomericmaterial.

In FIG. 13, the air output from discharge end 164 of nozzle 161 isfurther channeled due to the flow of the ambient air near discharge end164 of the nozzle. The ambient airflow is indicated by arrows 172. Theambient airflow near discharge end 164 of the nozzle corresponds to theairflow within the building which houses the vehicle drying system. Thisambient airflow results from the output of the other nozzles, as well asthe shape of the building itself.

The channeling of the nozzle output air according to the presentinvention is achieved by element 162, the geometry of nozzle 161, aswell as the flow of ambient air 172. This output air channeling causesthe air output at discharge end 164 to have a higher velocity and aproportionally larger directional component in the downward directionwhen compared to prior art nozzles. These features of the presentinvention, together with the oscillation and rotation of the nozzles asdiscussed above to yield the Coanda effect, allow smaller-sized blowercomponents to be used when compared to prior art devices while achievingsuperior results when compared to prior art devices. For example, atypical prior art system uses blowers having a rating of 40 hp, whereasthe present invention only requires blowers having a rating of 30 hp toyield superior results.

Another purpose of the nozzle configuration depicted in FIG. 13 is tosmooth out the otherwise pulsed nature of the air output from thenozzles. The blowers used for the dryer, such as blowers 126 and 128(FIG. 5) as well as prior art blowers, tend to output pulses of air asopposed to continuous airflow. These pulses are caused by theconfiguration of the blowers themselves, and particularly the design andspacing of the fan blades within the blowers. In the present invention,these air pulses are smoothed to yield a more continuous airflow byproviding element 162 as well as the constriction between outer surface162a of element 162 and curved wall 168 of nozzle 161.

FIGS. 14 through 16 more clearly illustrate the restrictions withinnozzle 161. FIG. 14 is a cross-sectional view taken along line 14--14 ofFIG. 13. The cross-sectional view in FIG. 14 has a diameter d1, andthus, a cross-sectional area of π(d1/2)².

As shown in FIG. 15, ovoid-shaped element 162 has a diameter d2 at itswidest point, and thus a cross-sectional area at its widest point ofπ(d2/2)². Therefore, the area A1 of planar section 174 is equal to π(d1/2)² -(d2/2)² !.

FIG. 16 depicts discharge end 164 of nozzle 161. Discharge end 164 has adiameter d3, so that the cross-sectional area of discharge end 164 isπ(d3/2)².

To achieve maximum benefit from the nozzle and ovoid-shaped elementconfiguration according to the present invention, it is desirable thatarea A1 of space 174 (FIG. 15) be slightly less than or equal to thearea of discharge opening 164 of the nozzle. In other words, π (d1/2)²-(d2/2)² !≦π(d3/2)².

FIGS. 17 and 18 are used to illustrate another important feature of thepresent invention, namely the Coanda effect. As referenced above, thepresent invention synchronizes the oscillation of the nozzles, andselects the speed of oscillation, the positions of the side nozzles, thearcs through which the side nozzles oscillate, the forward and rearwardrotation of the center nozzle, and the speed at which the dryer systemchanges position with respect to the motor vehicle (preferably at a rateof 15 cycles per second) to optimize the water removal from the motorvehicle by means of the Coanda effect. These components operate togetherto drive the water droplets down the sides of the vehicle, with theairflow tending to follow and cling to the contoured surface of thevehicular sides due to the Coanda effect.

FIG. 17 depicts water droplets 176 along a lower surface 178 of a motorvehicle. As shown in FIG. 17, water droplets 176 follow the contour ofsurface 178, and indeed will, despite gravity, cling to surface 178.

In FIG. 18, water droplet 186 is driven downward along surface 178 bythe airflow from the nozzles, represented by arrows 190. Airflow 190tends to follow curved surface 178, in accordance with the Coandaeffect. At the same time, droplets 192 are driven off of the vehicle byboth nozzle airflow 190 and the ambient airflow, represented by arrows194. By contrast, prior art dryers drove much of the water to the centerand rear of the vehicle, and indeed often drove the water upward againstgravity. As a result, significant amounts of water remained on the uppersurface of the vehicle when prior art dryers were used. However, thepresent invention uses a different approach to drying, resulting insignificantly improved water removal.

FIGS. 19 and 20 are schematic diagrams depicting the electronics used inthe dryer system according to the present invention. FIG. 19 is aschematic diagram of the low voltage side of the control electronics.FIG. 20 is a schematic diagram of the high voltage circuit used to powerthe motors and the dryer system.

Referring to FIG. 19, lines 196 together form an AC line power input.The AC line power is transformed to 24 volt power by a transformer 198,the transformer including a secondary winding 199. A fuse 200 isconnected on the secondary side of transformer 198. A DC power supply200 is connected across secondary winding 199, and is used to provide 24volts DC to two proximity switches 204 and 206.

The phase side of secondary winding 199 is connected to a fuse 208,which in turn is connected to a thermal couple switch 210 for heater212. Heater 212 is necessary since the dryer typically will not operatebelow 0° Celsius; switch 210 is set to close and thereby activate theheater at that temperature. Heater 212, which typically includes aresistive coil, has its negative side connected to line 24N.

AC lines 196 are also connected to power a programmable logic controller(PLC) 214. 24 volts of DC power is provided to PLC 214 via line 216. Asignal from the associated washer system is input on line 218 tocommunication pin 0 of PLC 214. The signal on line 218 informs PLC 214that the drying operation should begin.

The other inputs to PLC 214 are from the dryer sensors and proximityswitches. The output of the vehicular height measurement sensor 104(FIG. 4) is input to pin 1 of PLC 214. Similarly, the output of widthmeasurement sensor 44 (FIG. 1) is provided to pin 4 of PLC 214.Proximity switches 204 and 206 are used to override the widthmeasurement sensor to limit the travel of passenger side nozzle 30(FIG. 1) within prescribed limits. Sensor 204 limits the outward travelof nozzle 30, whereas sensor 206 provides a signal on pin 3 of PLC 214which instructs the PLC to stop the inward travel of blower 126 andnozzle 30.

Pins 200 through pin 204 comprise the outputs of PLC 214. Pin 200 isconnected to a contactor 220, which in turn is connected to an overloadrelay 222. Pin 201 of PLC 214 is connected to a contactor 224, which inturn is connected to an overload relay 226. Pin 202 is connected tocontactor coil 228, which in turn is connected to overload relay 230.Pin 203 is connected to contactor coil 232, which in turn is connectedto overload relay 230. Pin 204 is connected to contactor coil 234, andpin 205 is connected to contactor 236.

In FIG. 19, lines 270 and 272 are connected between washer 274 and theneutral side of secondary winding 199. A contactor coil 276 isinterposed between line 270 and a neutral side 24N of secondary winding199. A common line 24C of DC power supply 202 is connected to each ofsensors 44, 204, 206, and 104.

FIG. 20 depicts the remainder of the electronic control circuit. In FIG.20, AC line power is provided via lines 240 and 196. Line 244 isconnected to ground. Lines 240 provide AC line power to fan motor 130through contactor 220 and overload relay 222. Motor 130 is connected tolines 223 at a junction box 225.

Lines 196 provide AC line power to motor 138 through contactor 224 andoverload relay 226. Motor 138 is connected to lines 227 at a junctionbox 229. Lines 246 are connected to a circuit breaker (not shown)provided at the dryer installation site.

Lines 196 are connected through fuses 248 and 250 to contactors 220 and224 respectively. Lines 252 and 254 are connected between contactors 220and 224 respectively and a junction box 256. Motor 72 is connected tolines 252 and 254 at junction box 256.

Lines 196 also provide power to motor 46 through fuses 258, 260, and262, contactors 232 and 228, overload relay 230, and junction box 264.Fuses 266 and 268 are connected in series with lines 196.

The circuits depicted in FIGS. 19 and 20 operate in the followingmanner. After a vehicle has been dried, PLC 214 outputs a signal on pin202, thereby causing motor 46 to move nozzle 30 in an inward directionto the default position. When drying is to begin on the next vehicle,PLC 214 outputs a signal at pin 203, thereby causing motor 46 to movenozzle 130 in the outward direction. This outward movement continuesuntil a reflected signal is received by sensor 44, indicating that thewidth of the vehicle has been determined. PLC 214 then changes the stateof the signal at pin 203, thereby stopping motor 46.

Sensor 104 outputs a signal functionally related to the measureddistance between the upper surface of the motor vehicle and sensor 104.This output signal is received at pin 1 of PLC 214. In response, PLC 214may output a control signal at pin 205 to air cylinder 100 throughcontactor 236, thereby causing center nozzle 36 to rotate in either theforward or the rearward direction.

Also in response to the measured distance between sensor 104 and theupper surface of the vehicle, PLC 214 may output a signal at pin 204 tocontactor 234 and thus to damper solenoid 154 (FIG. 7), therebydampening or otherwise changing the output of center nozzle 36.

While a preferred embodiment of the present invention has been shown anddescribed, alternate embodiments will be apparent to those skilled inthe art and are within the intended scope of the present invention.Therefore, the invention is to be limited only by the following claims.

I claim:
 1. A dryer used to dry a motor vehicle, comprising:a firstnozzle; a second nozzle; a center nozzle disposed between said first andsecond nozzles; blower means for providing a gas at a high velocity tosaid first, second, and center nozzles; support means for supportingsaid first, second, and center nozzles; and means for changing theoutput of said center nozzle as a function of the distance between saidcenter nozzle and said vehicle.
 2. The dryer of claim 1, wherein saidchanging means includes:sensor means for outputting a signalfunctionally related to the distance between said center nozzle and saidvehicle; and valve means for receiving said output signal and forcontrolling the gas flow to said center nozzle in response to saidoutput signal.
 3. The dryer of claim 1, wherein each of said nozzlescomprises an open cell foam covered by an elastomeric material.
 4. Thedryer of claim 1, wherein said first nozzle and said second nozzle eachinclude:a side wall; a cavity defined by said side wall; and anovoid-shaped member disposed within said cavity and spaced from saidside wall.
 5. The dryer of claim 4, wherein said ovoid-shaped membercomprises an open cell foam covered by an elastomeric material.
 6. Thedryer of claim 1, wherein said side wall is comprised of a substantiallycurved surface.
 7. The dryer of claim 1, wherein said ovoid-shapedmember is substantially football-shaped.
 8. The dryer of claim 1,wherein said blower means includes:a first blower that provides a highvelocity gas to said first nozzle and to said center nozzle; firstconduit means for carrying the gas output by said first blower to saidcenter nozzle; a second blower that provides a high velocity gas to saidsecond nozzle and to said center nozzle; and second conduit means forcarrying the gas output by said second blower to said center nozzle. 9.The dryer of claim 1, further comprising:means for oscillating saidfirst, second and center nozzles in a synchronized manner.
 10. The dryerof claim 9, wherein said vehicle has a surface, and wherein thepositions of said first and second nozzles on said support means areselected and said oscillating means oscillates said first and secondnozzles at a selected velocity profile such that the high velocity gasoutput by said first and second nozzles follows the surface of saidvehicle.
 11. The dryer of claim 9, wherein said oscillating meansincludes:a motor; an elongated shaft rotatable by said motor; first,second, and third spaced eccentric cam members interconnected with saidshaft; a first connecting member having a first part interconnected withsaid first cam member and a second part interconnected with said firstnozzle; a second connecting member having a first part interconnectedwith said second cam member and a second part interconnected with saidsecond nozzle; and a third connecting member having a first partinterconnected with said third cam member and a second partinterconnected with said center nozzle.
 12. The dryer of claim 9,wherein said oscillating means oscillates each of said nozzles at avelocity that is substantially sinusoidal.
 13. The dryer of claim 1,wherein said first nozzle and said second nozzle each oscillate between4 degrees and 8 degrees.
 14. The dryer of claim 13, wherein said centernozzle oscillates between 30° to 40°.
 15. The dryer of claim 1, whereineach of said nozzles has a discharge opening, and wherein the area ofsaid center nozzle discharge opening is greater than the areas of saidfirst and second nozzle discharge openings.
 16. The dryer of claim 1,wherein the speed of oscillation of said first and second nozzles isbetween 12 and 15 cycles per minute.
 17. The dryer of claim 1, whereinsaid support means suspends said first, second, and center nozzles abovesaid vehicle.